Recombinant murine IL-10 produced in situ by H. pylori

描述(申请人提供)：幽门螺杆菌被称为当今世界上人类最常见的传染病。在世界范围内，50%-100%的人感染了幽门螺杆菌，但只有一小部分人出现了临床症状。近20年的研究已经形成了一个普遍的共识，即宿主免疫反应是决定感染结果的关键因素。幽门螺杆菌引起的胃炎是一种T辅助细胞-1介导的免疫反应，与高水平的干扰素-γ和低水平的IL-10及其他抗炎介质有关。 了解细胞因子在幽门螺杆菌所致胃炎中的作用，对诊断和治疗具有重要意义。首先，识别调节性细胞因子，如IL-10或TGFbeta，可能有助于进一步了解调节途径，并为那些患有难治性感染的人开发治疗方法。其次，或许同样重要的是，这种理解可能导致识别可能是应答者或非应答者的个人的能力。个体对幽门螺杆菌的反应差异很大，可能是因为每个个体宿主的免疫反应不同。由于IL-10与幽门螺杆菌免疫调节密切相关，我们选择将这项初步研究的重点放在IL-10上。 我们的总体目标是验证幽门螺杆菌原位产生的重组小鼠IL-10改善或预防小鼠胃炎的假设。这一目标将通过两个具体目标来实现： 目的1：构建表达重组鼠IL-10的幽门螺杆菌。 目的2：确定重组细菌或与重组菌株共定植的野生型幽门螺杆菌在体内的表达是否能预防或消除胃炎。 简而言之，我们将构建表达小鼠IL-10的重组幽门螺杆菌，证明细胞因子在培养和小鼠胃中由细菌表达，并确定这种表达是否可以改善或预防严重胃炎小鼠的炎症。成功的结果不仅将确定IL-10在幽门螺杆菌所致胃炎中的潜在治疗作用，还将建立一个模型，在此模型中可以确定其他细胞因子和介质的作用，并可以直接在体内评估宿主和细菌的相互作用。

DESCRIPTION (provided by applicant): H. pylori has been called the most common infectious disease of humans in the world today. Worldwide, between 50-100% of people are infected with H. pylori, but only a minority of those develop clinical signs of disease. Almost 2 decades of research have resulted in a general consensus that host immune response is a critical factor in determining the outcome of infection. Gastritis due to H. pylori is a T helper-1-mediated immune response associated with high levels of IFNgamma and low levels of IL-10 and other anti-inflammatory mediators. Understanding cytokine function in gastritis due to H. pylori has both diagnostic and therapeutic significance. First, identification of regulatory cytokines such as IL-10 or TGFbeta could lead to further understanding of regulatory pathways and development of therapies for those individuals with intractable infections. Second and perhaps equally important, such understanding could lead to the ability to identify individuals likely to be responders or non-responders. Individuals vary widely in their response to H. pylori, likely because of varying immunoreactivity of each individual host. Because of the strong association between IL-10 and immunoregulation of H. pylori responses, we have chosen to focus this pilot study on IL-10. Our overall goal is to test the hypothesis that recombinant murine IL-10 produced in situ by H. pylori ameliorates or prevents gastritis in mice. This goal will be accomplished in 2 specific aims: Aim 1: To engineer H. pylori to express recombinant murine IL- 10. Aim 2: To determine if in vivo expression leads to prevention or resolution of gastritis in response to recombinant bacteria or to wild-type H. pylori that co-colonize with recombinant strains. Briefly, we will construct recombinant H. pylori that expresses murine IL-10, demonstrate that the cytokine is expressed by bacteria in culture and in the mouse stomach, and determine if such expression ameliorates or prevents inflammation in a mouse model of severe gastritis. A successful outcome will not only determine the potential therapeutic role of IL-10 in gastritis due to H. pylori, but will also establish a model in which the roles of other cytokines and mediators can be determined, and host and bacterial interactions can be directly evaluated in vivo.